Valve for high pressure gas cylinders

ABSTRACT

This invention concerns a high rate discharge valve for high pressure gas cylinders provided with two separate openings, one for discharging and the other for refilling gas so that the empty cylinders can be refilled quickly and easily without disconnecting the valves from the gas discharge hose. This would indirectly make it possible to refill the cylinders on site, namely in the same room where the bank of cylinders is installed.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This patent application concerns a gas refill and discharge valve forhigh pressure gas cylinders. The valve according to the invention isdesigned to resolve the problem of refilling gas cylinders used in fixedfire extinguishing systems, namely those installed in offices orbuildings which are activated automatically following transmission of asignal by sensors placed in the areas monitored.

2. Description of Related Art

These extinguishing systems generally consist of a bank of large argonfilled cylinders each having a capacity of 140 liters, filled at apressure of 200 bar. It being evident that the larger the areamonitored, the higher the number of cylinders used will be.

BRIEF SUMMARY OF THE INVENTION

In consideration of the above, the new high rate discharge valve hasbeen designed with two separate openings, one for discharging and theother for refilling gas so that the empty cylinders can be refilledquickly and easily without disconnecting the valves from the gasdischarge hose.

Each cylinder is fitted with a high rate discharge valve opened by meansof actuators controlled by the signal received from the above peripheralsensors.

The major problem related to these systems is refilling the cylindersonce the extinguishing gas has been discharged in that this operation iscarried out at refilling centres to which the cylinders are transported.

Attention is drawn to the fact that the bank of cylinders is part of afairly delicate fixed system consisting of equipment, piping andinstruments which cannot be transported so that the system must first bedisconnected from the empty cylinders and then reconnected to therefilled cylinders; for safety reasons the system must be controlled andtested carefully whenever the cylinders are removed and replaced.

Moreover, the empty and refilled cylinders must be transported carefullywith appropriate means in that during transport there is the risk ofdamaging delicate components of the cylinders such as the abovementioned high rate discharge valves, the pressure gauges or thethreaded bronze connections.

Transport of the cylinders is thus not only difficult but may also bedangerous for the operators in view of the weight of the cylinders andthe high pressures involved which in fact render all the variousoperations hazardous.

The high rate discharge valves currently available on the market do notpermit refilling the cylinders without disconnecting the same from thegas discharge hose in that said valves are provided with a singleopening through which the argon gas is discharged and refilled.

A valve of the type mentioned above is described in U.S. Pat. No.3,860,073. In said patent the valve has the connection designed both forrefilling the cylinder and to actuate the discharge of the fireextinguishing system. In order to refill, with this type of valve it isnecessary to disconnect the manual/electric actuator, connect therefilling connector and refill all the cylinders; in addition, sincesaid valve is designed for two-phase fluids, it is necessary to firstconnect the refilling pipe of the fluid in its liquid state and then thenitrogen pressurisation pipe. By means of all these the automatic fireextinguishing system is totally shut down since all the actuators aredismounted from the pilot cylinders.

In consideration of the above, the new high rate discharge valve hasbeen designed with two separate openings, one for discharging and theother for refilling gas so that the empty cylinders can be refilledquickly and easily without disconnecting the valves from the gasdischarge hose.

This would indirectly make it possible to refill the cylinders on site,namely in the same room where the bank of cylinders is installed,obviously by providing a network of auxiliary piping therefor throughwhich the cylinders are supplied; in other words said auxiliary systemwill on one hand be supplied from a point outside the storage roomaccessible to the refilling tanker and on the other will supply eachindividual cylinder whose high rate discharge valve will be connectedpermanently both to the refilling system and to the extinguishingsystem.

Refilling can therefore be carried out without removing and transportingthe cylinders but simply by opening and closing the valves.

Although the valve according to the invention operates like a standardhigh rate discharge valve, the new valve is characterised by the factthat the following three sections, which in standard valves are groupedinto a single section, have been physically separated:

gas discharge section;

pressure intake section for the installation of pressure gauges andpressure switches for detecting the lack of minimum pressure conditions;

refilling section.

For major clarity the description of the valve according to theinvention continues with reference to the enclosed tables which areintended for purposes of illustration and not in a limiting sense,whereby:

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A, 1B and 1C are three views of the valve in question.

FIG. 2 is a cross-section on plane A—A of FIG. 1A, illustrating thevalve in closed position.

FIG. 3 is a cross-section on plane B—B of FIG. 1A, illustrating thevalve in closed position.

FIG. 4 is a cross-section on plane A—A of FIG. 1A, illustrating thevalve in discharge position.

FIG. 5 is a cross-section on plane B—B of FIG. 1A, illustrating thevalve in discharge position.

FIG. 6 is a cross-section on plane B—B of FIG. 1A, illustrating thevalve in refilling position.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to the above drawings, valve (1) according to theinvention consists of a valve-body (2) terminating at the bottom with athreaded connection (3) screwed into the outlet of the cylinder (notshown in the figure).

The axial duct (3 a) provided in said connection (3) terminates in acircular chamber (4) obtained in the valve-body (2) along whose lateralwall are provided three holes (5, 6 and 7), staggered by 90° while onthe “roof” of said chamber (4) there is a central hole (8) forming theinlet of an overlying ascending duct (9) that opens at the top into acylindrical chamber (10) formed on the valve-body (2) and sealed by acap (11) screwed on the exterior of said cylindrical chamber (10).

Within said chamber (10) is housed, sealed and slides a piston (12), therod (13) thereof being fitted and guided within said axial duct (9) andopening into the circular chamber (4).

It being provided that at the bottom end of said rod (13) is screwed ashutter plate (14), fitted with a gasket (14 a), that hermetically sealsthe inlet hole (8) of the overlying duct (9) thanks to the traction of areturn spring (15) fitted on the rod (13) that constantly exerts alifting thrust on the piston (12).

The hole (5) forms the housing and sliding seat of a plug (16) on theback of which is fitted a gasket (16 a) and a pin (16 b) sealing a smallhole (17 a) that opens externally at the centre of a connection (17) onwhich is mounted the actuator (not shown) that opens the valve in caseof fire.

It being provided that said connection (17) intercommunicates, by meansof a duct (18), with the space (18 a) between the cap (11) and thepiston (12).

A nipple (6 a) for the pressure switch (19) being screwed into the hole(6) and the pressure gauge (20) being fitted into the hole (7).

Along duct (9) is provided a radial branch (9 a) that crosses and opensinto gas outlet connection (21), while along duct (3 a) is provided ahole (22) that opens externally into a threaded seat where the refillvalve (23) is screwed.

When the valve is closed, the gas in the cylinder cannot escape fromchamber (4) and from duct (3 a) in that all the outlet holes provided inthe same are hermetically sealed as follows:

hole (8) is closed by the plate (14);

hole (22) is closed by the refill valve (23);

hole (17 a) is closed by the plug (16).

It being provided that valve (1) opens when the actuator pushes againstthe pin (16 b) so as to move back the plug (16) allowing the gas to flowthrough hole (17 a) into the connection (17) and into the space (18 a)through the duct (18); consequently the piston (12) is lowered and thehole (8) is opened by the plate (14) so that the gas rises up the duct(9) and is discharged to the exterior through the branch (9 a), as shownin FIG. 5.

The refill valve (23) is a standard one-directional valve, consisting ofa ball subject to the thrust of a spring.

The number (24) refers to the safety outlet through which the gasescapes if its pressure exceeds a preset value; it being provided thatsaid safety outlet includes a safety disc (24 a) dimensioned to breakwhen the pressure reaches said preset maximum value.

What is claimed is:
 1. A valve for high pressure gas cylinder of thetype consisting of a valve-body (2) terminating at the bottom with athreaded connection (3) whose internal duct (3 a) opens into a circularchamber (4) the “roof” of which is provided with a central hole (8)forming the inlet of an overlying ascending duct (9) that opens at thetop into a cylindrical chamber (10), formed on the valve-body (2) andsealed by a cap (11) screwed on the exterior of said cylindrical chamber(10), in which a piston (12) is housed, sealed and slides, wherein a rod(13) thereof is fitted and guided within the axial duct (9) andsupports, at its bottom end, a shutter plate (14) fitted with a gasket(14 a) that hermetically seals the inlet hole (8) of the overlying duct(9) thanks to the traction of a return spring (15) fitted on the rod(13) that constantly exerts a lifting thrust on the piston (12): a—avalve characterised in that: a radial branch (9 a), that supplies a gasoutlet connection (21), is provided along duct (9); b—a hole (22), thatopens externally into a threaded seat where a refill valve (23) isscrewed, is provided along duct (3 a); c—three holes (5, 6 and 7),staggered by 90°, are provided along the lateral wall of said chamber(4), wherein: the first hole (5) forms a housing and sliding seat of aplug (16) on the back of which is fitted a gasket (16 a) and a pin (16b) sealing a small hole (17 a) that opens externally at the centre of aconnection (17) on which a valve opening actuator is mounted and whichintercommunicates by means of a duct (18) with a space (18 a) betweenthe cap (11) and the piston (12); wherein a nipple (6 a) for pressureswitch (19) is screwed into the second hole (6); wherein a pressuregauge (20) is fitted into the third hole (7).